High-frequency transformer



Dec. 9, 1930. H. G. MAERLENDER' ET AL 1,784,297

HIGH FREQUENCY TRANSFORMER 7 Filed May 151, "1929 s Sheets-Sheet 1 2a 15Alla-Wm.

H060 A. HEA/AVG aww Q. W arrm/van Dec. 9, 1930. H. e. MAERLENDER ET AL1,734,297

RIGH FREQUENCY TRANSFORMER Filed May 51, 1929 s Sheets-Sheet s PatentedDec. 9, 1930 {UNITED s r Ts HENRY G. MAERLENDER [1ND HUGO .A.MAERLENDER, OF CLEVELAND, OHIO HIGEFREQUENGY TRANSFORMER Applicationfiled May 31, 1929. Serial No. 367,530.

Ourinvention relates to inductances and high frequency currenttransformers. It re-s li objects include the coupling of such inductances in parallel and will appear more fully hereinafter.

WVhile in the annexed drawings only one form of our invention is shown,corresponding parts and electrical equivalents are within the spirit ofour invention including inferior structures and portions of suchinvention as shown. r 1

In said annexed drawings p Figure 1 is a front elevation of one of ourimproved transformer assemblies:

Figure 2 shows a vertical section on the line 2-2 of Figure 1, certainparts being shown in elevation V Figure 3 is an enlarged axial sectionthrough one of the individual units of our transformer assembly; I

Figure 1 is a horizontal section on the line 4-1 of Figure 1, showingthe method ofsupporting the units; 1

Figure 5 shows a horizontal section onthe line 55 of Figure 1, showingthe method of completing the circular assembly;

Figure 6 is an enlarged view of awedge shown in Figure 5;

Figure 7 is a diagrammatic View of the wiring, each helix beingindicated bya simple loop, and the number of transformer coils beingless than the number shown in Figure 1 for the sake of clearness; and

Figure 8 is a side elevation of a smaller transformer built inaccordance with this invention, having'a section broken away to show asimpler form of transformer coil construction.

Referring to the same parts throughout the several views by the samereference characters we designate an antenna by the letter A in serieswith a variable condenser C the ground side being joined to conductor 1which is connected to one end of the circuit conductor 1 which is almostcompletely closed and is supported by the upper arm of the bracket 13and the lower arm of bracket 12 in the manner shown in Figure 2, bothbrackets being bolted to the base 11. The circular conductor 3 is thesame size as conductor fl and is supported by the upper arm of bracket13 and the lower arm of bracket 12 on the op posite side ofconductor 4.Conductor 2 is connected to conductor 3 at the relativelyopposite endfrom the junction'of conductors 1 and 4. Conductor 2 is directlyconnected to the ground Gr.

Concentric with and inside of the conduc- To tors 3 and 4% are theconductors 5 and 6 supported by the lower arm of bracket 13 and theupper arm of bracket 12. The circular disc 9 is bolted verticallyequidistant from conductors 3 and 5 and 4 and 6 to the bracket 12 7 asshown in Figure 4. The disc 9 is hollow in v the center and has aV-shaped opening at the Single inductance units L consists of cyltoinders 14 having enlarged exterior peripheral abutments 15 at both endsso as to form a retaining guide forthelayers of wire which consist ofthree single layers of insulated wire, each having the same number ofturns. The middle layer terminates preferably on the opposite side ofthe cylinder from the terminals of the inner and outer rows.

The ends26'and 27 of the inner and outer helixes respectively passingthrough the groove 21 of the peripheral abutment 15 and being connectedto the external conductor 20. Similarly the opposite ends 2 1 and 25 ofthe inner and outer helixes pass through the groove 23 and are joined tothe external conductor 19. Ehe terminals of the single layer passthrough the grooves 16 and 22 and are soldered tothe external conductors17 and 18 respectively. The interior diameter of each single inductanceunit L is preferably about 3 inches so that its length will berelatively small in comparison with its cross section.

The width of the annular disc 9 measured in a radial direction is madethe same as that of the inside diameter of the inductance units L sothat it may snugly accommodate them when they are slid into position onthe disc 9 through the V-shaped opening in the top. Inductance units Lare slid to the lower or closed side of the annular disc 9 as close toone another as desired, care betaken that the electricallycorrespondterminals of all coils are always on the same side, theterminals 19 and 20 connected with the inner and outer coils being Sl10\n on the inner sides. The last coil L is slipped over the V-shaped piece10 which slides into the groove of the cylindrical section 9 andcompletes that circle. The connections 19 and 20 are bent laterally inopposite directions. Likewise, connections 17 and 18 are bent laterallyin opposite directions, conductors 19 and 18 both bent rearwardly andconductors 20 and 17 being bent forwardly, being in the same direction,All of the conductors 19 are joined at substantially right angles withthe circular conductor 5; conductors 20 with the conductor 6; conductors18 with conductor 3 andconductors 17 with conductor 4. Conductors 7 and8 are joined with the circular conductors 5 and 6 respectively at theirrelatively opposite ends preferably in the same manner as conductorsland 2 are connected to conductors 4- and 3. Thus the current path isequal in length and resistance for all inductance units and no variationin inductance from this cause is possible.

As depicted in Figure 8 each unit L consists of a primary helix P and asecondary helix S. The same relative ends of each primary helix arejoined to conductors 3 and 4t, and likewise, the same relative ends ofthe secondary helices are joined to conductors 5 and (3. Thereby theprimary helices are connected in parallel as are the secondaries. Inreading this figure attention is called to the fact that the terminalsof the primary and secondary helices are on opposite sides of the unitL; that is, the primary terminals are shown in dotted lines.

By reason of the circular or annular disposition of the coils eachinductance is similarly acted upon by all of the rest and no ci'iange intheir individual inductances is possible from this cause. Such adisposition is necessary where a great number of coils are employed. Twosuch coils could be placed side by side without either diminishing thecurrent or affecting the inductance of each.

The construction of each unit L permits of 100 per cent transfer ofenergy from pri mary to secondary. The inner and outer helicescomprising the secondary absorb all of the energy from the primaryhelix, being coupled as closely therewith as insulation and practicalconstruction permits.

The value of this inductance is of speciai importance in combinationwith the circuit shown. Condenser C of Figure 7 is joined in parallelwith the conductors 8 and 7 which form the output of the high frequencyre- *eiving system. The primary and secondary helices should preferablyhave the same number of turns so that there will be no transformationloss.

It is, of course, also apparent that each of the inductance units L,instead of being perfect transformers, could consist of primary andsecondary coils loosely coupled together so that each inductance byreason of the transformation loss would in itself have characteristicstendin to produce selectivity in a radio receiving system.

A satisfactory construction is shown clearly in Figure 8 in whichindividual primary and secondary inductances are shown preferablyclosely coupled together, although it is obvious that by changing theamount of flux interweaving each individual primary and secondary or bychanging the amount of inductance in either they could be made so as tobe loosely coupled.

Varying the angle formed by the axes of the primary and secondary coils,reducing the number of turns in either coil, thereby altering theinductances and spacing one coil from the other in order to reduce theintensity of the flux are common expedients for producing looselycoupled transforn'ier coils.

Under all conditions, whether the coils be made as shown or looselycoupled, the individual inductance units L must be similar to eachother, preferably identical, in selfinductanceof both primary andsecondary and mutual induction of primary and secondary, in order thatthere may be no loss when a great number of inductance units areemployed to attain any desired degree of selectivity.

Vhat We claim is:

1. A high frequency current transformer comprising a plurality ofmagnetically independent primary inductance elements joined in paralleland secondary inductance 'elements, each comprising two sectionsconnected in parallel and severally coupled interiorly and exteriorly ofeach of said primary inductance elements, all of said secondaries beingconnected in parallel.

2. A high frequency current transformer comprising a plurality ofindependent equal primary inductance elements circularly disposedequidistant from each other on an annular disc; secondary inductanceeach comprising two sections connected in parallel and severally coupledinteriorly and exteriorly of each of said primary inductance; and

circular conductors disposed adjacent said annular disc to which theends of both primary and secondary inductances are respectively joined.

3. A high frequency current transformer comprising a plurality ofindependent equal primary inductances circularly disposed equidistantfrom each other on an annular disc; two circular shaped conductorselectrically disconnected at one point disposed adjacent both sides ofsaid disc concentric with one another and one on either side beingjoined with said primary inductances; equal secondary inductancesseverally coupled interiorly and exteriorly of each of said primaryinductance, all being successively joined in parallel with the remainingcircular shaped conductors; and output conductors for both primary andsecondary circuits be ing joined at the relatively opposite ends of bothprimary and secondary circuits.

4. As an article of manufacture and sale a high frequency currenttransformer comprising a primary helix and secondary helices coupledinteriorly and exteriorly thereof and joined in parallel.

5. As an article of manufacture and sale a high frequency currenttransformer comprising a plurality of independent equal primaryinductances circularly disposed equidistant from each other on anannular disc; two circular shaped conductors electrically disconnectedat one point disposed adjacent both sides of said disc concentric withone another and one on either side being joined with said primaryinductances; equal secondary inductances severally coupled interiorlyand exteriorly of each of said primary inductances all beingsuccessively joined in parallel with the remaining circular shapedconductors; and output conductors for both primary and secondarycircuits being joined at the relatively opposite ends of both primaryand secondary circuits.

6. As an article of manufacture and sale a high frequency currenttransformer comprising a plurality of independent equal primaryinductances circularly disposed equidistant from each other on anannular disc; two circular shaped conductors electrically disconnectedat one point disposed adjacent both sides of said disc concentric withone another and one on either side being joined with said primaryinductances and equal secondary inductances severally coupled with eachof said primary inductances, all bein successively joined in parallelwith the remaining circular shaped conductors; and output conductors forboth primary and secondary circuits being joined at the relativelyopposite ends of both primary and secondary circuits.

7; A high frequency current transformer comprising a plurality ofmagnetically independent equal primary inductance elements substantiallydisposed in a circle and equidistant from each other and equal secondaryelements severally coupled with each ofsaid primary inductance elementsand joined in parallel. j p p 8. A high frequency currenttransformercomprising a plurality of magnetically independent inductance elementsjoined in parallel and equalsecondary elements each comprising twosections connected in parallel and severally coupled interiorly andexteriorly of each of said primary inductance, all of said secondariesbeing connected in parallel.

9. A high frequency current transformer comprising a plurality ofmagnetically independent equal inductance elements substantiallycircularly disposed. radially equidistant from each other; equalsecondary inductance elements severally coupled with each of saidprimary elements and severally intercepting the flux thereof andconductors disposed adjacent the ends of the inductance elements towhich both primary and secondary elements are respectively oined.

10. As an article of manufacture and sale a high frequency currenttransformer comprising a plurality of magnetically independent equalprimary inductances substantially circularly disposed equidistant fromeach other on an annular disc; two circular shaped conductorselectrically disconnected at one point disposed adjacent both sides ofsaid disc concentric with one another and one on either side beingjoined with the ends of said primary inductance; equal secondaryinductances each comprising two sections connected in parallel andseverally coupled interiorly and eXteriorly of each of said primaryinductance, all being successively joined in parallel with the remainingcircular shaped conductors substantially as illustrated and described.

11. As an article of manufacture and sale g the remaining circularshaped conductors severally coupled as illustrated and described. I

12. A high frequency energy distributing device comprising a pluralityof primary inductances of substantially equal inductance value andsubstantially electromagnetically independent but arranged to have theirmutual stray fields equalized and said inductances being electricallyjoined in parallel and secondary inductances severally coupled with eachof said primary inductances and similarly disposed and joined inparallel.

13. A high frequency transformer comprising two primary helices ofsubstantially equal inductance value and substantiallyelectromagnetically independent but arranged to have their mutual strayfields equalized and said inductances being electrically joined inparallel and secondary inductances of substantially equal inductanceseverally coupled with each of said primary inductances and joined inparallel.

HENRY G. MAERLENDER.

HUGO A. MAERLENDER.

